In this image you can observe a group of unicellular ciliate organisms belonging to the Kingdom Protista. Their name is Vorticella and they have an inverted bell shape. The ciliates are all anchored onto a small fragment of substrate due to a contractile stalk called a myoneme. When stimulated, this shortens, causing the stalk to coil like a spring. The cilia from the head of the Vorticella make a current of water (vortex) in order to catch the food around (bacteria and other protozoa).